Local Group

American  

noun

Astronomy.

1. the group of galaxies, at least 25 of which are known, that includes the Milky Way.

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Local Group British  

noun

1. astronomy the cluster of galaxies to which our galaxy and the Andromeda Galaxy belong

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Local Group Scientific  

1. A group of more than 30 galaxies that includes 2 large spiral galaxies—the Milky Way and Andromeda—as well as numerous smaller galaxies, many of which are dwarfs. The Local Group has a diameter of approximately 10 million light-years, with its gravitational center located between our galaxy and the Andromeda galaxy. It is part of a larger grouping known as the Virgo supercluster.

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Etymology

Origin of Local Group

First recorded in 1915–20

Example Sentences

Despite the gravitational pull of the Local Group, galaxies within the plane are influenced by additional mass spread throughout that same plane.

From Science Daily • Mar. 6, 2026

The resulting simulations replicate the masses, locations, and motions of the Milky Way and Andromeda, as well as the positions and velocities of 31 galaxies just outside the Local Group.

From Science Daily • Mar. 6, 2026

Using advanced computer simulations, the researchers discovered that the matter surrounding the Local Group is arranged in a broad, flattened structure that stretches tens of millions of light-years across.

From Science Daily • Mar. 6, 2026

It turns out that the Milky Way Galaxy is a member of a small group of galaxies called, not too imaginatively, the Local Group.

From Textbooks • Oct. 13, 2016

But presently our journey takes us to what astronomers on Earth like to call the Local Group of galaxies.

From "Cosmos" by Carl Sagan